<!DOCTYPE html>
<html>
<head>
  <title></title>
</head>
<body>
  <div id="app">
    <counter :count="count"></counter>
    <counter :count="count"></counter>
    <counter :count="count"></counter>
    <button @click="count++">increment</button>
  </div>
  <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
  <script>
    new Vue({
      el: '#app',
      data: { count: 0 },
      components: {
        Counter: {
          props: ['count'],
          template: `<div>{{ count }}</div>`
        }
      }
    });
  </script>
</body>
</html>
